The present invention is related to a method, an apparatus, and a program for evaluating the image quality of target structures such as a liver, which is included in a three dimensional image.
Recently, pre surgical planning is being performed prior to performing surgical procedures. The pre surgical planning is performed by obtaining a three dimensional image generated from a plurality of tomographic images, such CT (Computed Tomography) images and MRI (Magnetic Resonance Imaging) images. Next, an organ which is to be the target of the surgical procedure is extracted from the three dimensional image. Then, the extracted organ is employed to execute the pre surgical planning to determine which portion of the organ is to be excised. Particularly, in the case that a structure having lumen structures in the interior thereof, such as the portal vein of the liver, is the target of the surgical procedure, the liver and the portal vein are extracted from the three dimensional image. Next, the dominated region of each branch of the portal vein is determined based on the distribution of the porta vein. Then, pre surgical planning is performed to determine the dominated region to be excised by the surgical procedure. Here, the dominated region refers to a region to which blood is supplied by portal veins toward the distal ends of branches, in the case of the liver.
In addition, the degree of reliability, which represents the appropriateness of pre surgical plans, is being evaluated by comparing the results of pre surgical plans, which are generated from three dimensional images obtained at medical facilities according to imaging conditions at each of the medical facilities, and the results of actual surgery (refer to T. Takamoto et. al., “Planning of anatomical liver segmentectomy and subsegmentectomy with 3-dimensional simulation software”, The American Journal of Surgery, Vol. 206, Issue 4, pp 530-538, 2013).
In addition, a technique for calculating the degree of reliability of extraction results of organs and the like has also been proposed (refer to Japanese Unexamined Patent Publication No. 2009-98644). In this technique, statistical amounts, such as the average values of measured values of anatomical features (the lengths, the areas, the volumes, the shapes, the orientations, and the positional relationships) of organs and lumen structures, which are extracted from tomographic images, are obtained. Then, whether the statistical amounts are within ranges which are set in advance is judged. In addition, a technique that obtains statistical amounts such as average values from analysis results of images, and calculates the degree of reliability of the analysis results based on the statistical amounts has also been proposed (refer to Japanese Unexamined Patent Publication No. 2014-100555).